Crocker said at a news conference he "laid out before the Iranians a number of our direct, specific concerns about their behavior in Iraq."

U.S. officials have long accused Iran of supplying Iraqi insurgents with deadly weapons and training, an accusation the Iranian government has denied.

Crocker said he told the Iranian diplomats that Iran's actions in Iraq "need to cease," the Times reported.

Iran had no immediate comment on the talks. Crocker said the Iranian delegation's focus was on "mechanisms, if you will, and principles, rather than the detailed security substance that we need to see improvement on."

The United States broke diplomatic ties with Iran in 1980 in the middle of the hostage crisis at the U.S. Embassy in Tehran.